The U.K.’s governing Conservative Party headed for a fresh civil war over Europe as Theresa May prepared for a showdown with her lawmakers that could hasten the end of her premiership.

The botched election campaign opened a new front in the Tories’ decades-long internal conflict over Britain’s membership of the European Union. Some of May’s most senior ministers are plotting to soften her approach to leaving the bloc, potentially keeping the country in the single market and customs union. By contrast, hard-line Brexit supporters are determined to force through the prime minister’s plans for a clean break.

Potential leadership rivals Foreign Secretary Boris Johnson and Brexit Secretary David Davis pledged their loyalty to May, saying it was the wrong time for a change at the helm or another general election. Yet the mood in Westminster remained that she’s on borrowed time with the question only when rather than if she will be deposed.

Jonathan Brady/PA Wire

“Her MPs could call time on her premiership at any moment,” said Mujtaba Rahman, managing director at the Eurasia Group. “More likely, however, is that she would avoid such humiliation, bow to the inevitable and announce her resignation.”

May will chair a meeting of her new cabinet on Monday, before hearing first-hand the anger of Tory members of Parliament who blame her for the catastrophic election campaign that cost the Conservatives their parliamentary majority.

In a round of broadcast interviews on Monday, Davis — a leading euroskeptic — stuck by May’s original plan for leaving the single market in return for reclaiming control of borders and laws.

“The reason for leaving the single market is not particularly because we want to, but because the single market requires the free movement of people,” Davis told LBC radio on Monday.

DAN KITWOOD/AFP/Getty Images

He said questions over May’s future were “unbelievably self-indulgent” and vowed he would work to entrench her in her position so she could deliver the best Brexit deal for Britain. “What you’re going to see over the next weeks and months is Theresa May at her best,” he told the BBC.

However, he conceded that last week’s election result “clearly makes it a bit more difficult to start” Brexit negotiations, which are scheduled to begin in a week’s time.

Wheatley/WENN

May’s plans have been thrown into chaos along with the U.K.’s entire political landscape by Thursday’s vote. The premier was unable to carry out wholesale cabinet changes that had been mooted before the election, with most ministers staying in the same jobs. She even resorted to giving her former adversary Michael Gove a role in her cabinet, after sacking him last year.

The appointment of Damian Green — a passionate pro-European — as her new deputy is being taken as a sign that she wants to keep anti-Brexit lawmakers on side.

Some of May’s own ministers see opportunities to use her weakness to soften plans for Brexit, even suggesting the U.K. could remain in Europe’s single market and customs union.

May is now so reliant on the support of political rivals inside and outside her party that she’ll be unable to force through her vision for Brexit, according to three senior government officials who didn’t want to be named discussing sensitive matters.

Wheatley/WENN

May will meet with the Democratic Unionist Party leader Arlene Foster in London on Tuesday in the hope of finalizing a deal that will allow her to pass laws in Parliament and keep her party in power.

May wants the support of the DUP’s 10 lawmakers to make up for the Tories’ nine-seat shortfall in the Commons. The Conservatives will be unable to pass controversial legislation without the DUP, the only minor party willing to countenance backing May.

May is already planning to drop other pledges from the Tory manifesto that would be too difficult to get through Parliament, The Daily Mail reported late on Sunday, without saying where it got the information. Davis conceded that some commitments could be “pruned away.”

On Monday, the Tory leader will gather her new cabinet together for the first time. Though she’s unlikely to face a tough grilling at this meeting of her top team, May is certain to be challenged over the disastrous election result when she appears before the 1922 Committee of rank-and-file Tory lawmakers.

She will also face demands to spell out the details of her proposed deal with the DUP.

“Obviously my colleagues are very disappointed,” Graham Brady, chairman of the 1922 committee, told Sky News. “I don’t think there’s any clamor for another election and certainly I don’t see any clamor from my colleagues for another leadership election.”